Method of treating plastic material.



PATENTBD MAR. 27, 1906.

A. A. SCOTT.

METHOD OF TREATING PLASTIC MATERIAL.

APPLIOATIONYIILED NOV. 13, 1905..

4 SHEETS-SHEET 1.

IVitnemea.

No. 816,386. PATENTBD MAR. 27, 1906.

- A. A. soon,

METHOD OF TREATING PLASTIC MATERIAL.

APPLICATION FILED NOV. 13, 1905.

4 SHEETS-SHEET 2.

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4 C] U U I: E] D D C! D M w w'ysw y w W I M i 7 Law/9% Attorney No.816,386. PATENTED MAR. 27, 1906.

A. A. SCOTT.

METHOD OF TREATING PLASTIC MATERIAL.

APPLICATION IIIIED NOV. 13, 1905. v

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PATENTED MAR. 27, 1906.

A. A. SCOTT. 1 METHOD OF TREATING PLASTIC MATERIAL.

APPLIGATION FILED NOV. 13, 1905.

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UNITED STATES PATENT oEE-IoE.

ALEXANDER ANDERSON SCOTT, OF KNOXVILLE, TENNESSEE.

- METHOD OF TREATING PLASTIC MATERIAL.-

Specification of' Letters Patent.

Patented March 27, 1906.

To all whom it may concern: V

Be it known that I, ALEXANDER ANDERSON SCOTT, a citizenof the UnitedStates, residing at Knoxville, in the county of Knox and State ofTennessee, have invented a new and useful Improvement in Methods'ofTreating Plastic Material, of which the following is'a specification,reference being had to the accompanying My improvement relates generallyto methods of treating clay and analo ous lastic material for themanufacture 0% bric tile, and analo ous artificial products requiringdrying un er relatively moderate temperature and subsequent burningbeing subjected to an intense heat; and t e improvewet or green.

ment relates particularly to the manufacture of such products from whatis termed stiff. clay in the clay-working art, the term soft clay beinapplied to those clays which are so plastic w en formed intogreen bricksthat such bricks must be set in single courses for drying, (theplasticity being such that each individual br ck would be pressed out ofform by the weight of another brick placed u on it,) and the term drybeing applie to clays from which bricks may be formed suf-' ficientlyfirm to permit piling orsetting in .a

kiln as high as is ordinarily desired for burn ing. A proximatelseventy-fiveper cent. of the rick manu actured in this countryThroughout this rily, to the manufacture of clay products from suchstiff clays, and, secondarily, to the manufacture of clay products fromsuch soft clays.

locks of clay for the manufacture of brick and analo ous products areformed from clay which has een rendered plastic and cohesive by mixingit with enough water to make itmoist or wet, and such blocks are said tobe Before these blocks so formed can be burned the water which theycontain must be eliminated from them. Here tofore in the manufacture ofstiff-clay brick this has usually been done in twosteps, the

first of said steps being the slow dryingat a relatively lowtemperature, from ap roxi-' mately 100t0 600 Fahrenheit, whi e the.brickare set upon each other in from about- 'five' t'o'ten tiers .orcourses (it,being necessary tolimit the number of courses because the- Vblock's-are plastic and are not able to withstand any considerablepressure-without changingshape I account-of said pressure) smoking.

and t e second step being the placing of the bricks into a kiln andafter being set as high as is desired for burning subjecting them to a.higher drggng heat ranging from 500 to 1,000? Fa enheit until theremnant of water not eliminated by the first step of drying has beeneliminated. This second step of drying is by some manufacturers calledwatercurrents of air or other gaseous medium which is capable of takingup moisture from said blocks and carrying said moisture away,

whereby the amount ofmoisture contained by said blocks is gradually moreand more reduced. For the sake of convenience in de- In a general way itmay be stated that the green brick are subject to carry away moisturevaries toa large extent with the temperature of the gaseous medium, andthe rapidity with which said moisture is eliminated from said blocksmust vary according to variations in the quality of the clay. For someclays the absorption during the first stages of the drying must be slowin order to avoid checking said blocks. stances it is desirable to beginwith currents of air which are of low temperature (so that they willabsorb slowly) or which are nearly saturated with moisture, so that theycan take'but little more moisture thanthey alread hold. Somemanufacturers perform In some inthis r st step of-drying b exposing thebricks. v

in low piles to the suni ht and to natural currents of airat normatemperature; but according to the prevailing practice said bricks-arelaid or set on trucks in a limited number of courses and on said trucksput into an inclosure or structure termed a drier and there subjected tocurrents of air at a relatively low temperature-from approximately .to600 Fahrenheituntil the plasticity of the bricks has been sufficientlyreduced to permit setting to the heightdesired for burning from aboutthirty to fifty courses high; Such method is undesirable, because itnecessitates expendlture for the construction and maintenance of thedriers and requires extra handling of the bricks, and the method is notadapted to the mechanical' handling of the brick direct from the machineto the and because there loss of heat in transferring the brick from thedrier into the kiln.

The objects of my invention is to reduce the cost of mechanicalequipment, to reduce the handling of the brick, to allow such handlinggether dispensed with and the bricks are set in the kiln direct from themachine in the green or wet state and are not again moved until theyhave been both dried and burned.

By way of general description it may be stated that my improved methodinvolves setting the green or wet blocks in the kiln in a group, belt,or zone to only such hei ht as will avoid crushing the lower of said bocks, then drying said blocks, and thereby ren'der ing them sufficientlyfirm to support greater pressure from above, then setting upon thegroup, belt, or zone of blocks thus dried another group, belt, or zoneof green blocks, then drying-the blocks of saidsecond grou belt. orzone, then setting a third group, be t,

or zone of green or wet blocks upon said sec- 0nd group, then dryingsaid third group, and so on until the total height of all said'groupsaggregates the height desired for the burning oi said blocks.

For the sake of economy the practice of my method may, if so desired,also include the utilization of the heated air (termed "waste heat inthis art) coming from a charged kiln during the cooling period after thecharge has i been burned and the products of combustion coming from acharged kiln during the bur 1r ing period, said heated air orsaidproducts of combustion being drawn through suitable ducts into akiln or compartment of a kiln in which a group of green brick has beenset ready for drying. As to economy, it may be noted that by my improvedmethod the saving of labor after the stream of lastic material leavesthe machine is fully fi ity per cent. Besides this item, there is asaving of heat. Furthermore, the cost of mechanical e ui;p-' ment isreduced approximately one-hal The present invention is a modification ofthe method described in an application for Letters Patent of the UnitedStates filed by me October 12, A. D, 1905,Serial No. 282,414.

My improved method may be practiced or carried out by various mechanicalmeans. As examples of such means I refer to the. apparatus illustratedby the accompanying drawin s.

' In said drawin s, Figure 1 is a transverse upright section 0 anopen-top kiln adapted for the practice of said method, said sectionbeing on the line 1 1 of Fig. 2. Fig. 2 is a sectional plan of the samekiln. Fig. 3 is a diagrammatic plan showing a group of three kilns andunderground ducts communicating While the duct 11 leadsto s'aidfan.

withsaid kilns. Fig. 4 is a transverse u right section of a closed kilnadapted to t e practice of said method, said section being on the line 44 of Fig. 5. Fig. 5 is a sectional plan of the kiln shown in Fi 4. Fig.6 is an upright cross-section of a kiln similar to that shown in Fig 4,but having furnaces at only one side and having smoke-stacks or chi'mneys. Fig. 7 is a detail plan of a modification. I

Referring first to Figs..1 and 2, 1 is the floor of the kiln. 2 2 arethe side walls. 3 3 are the end Walls, and. 4 is a roof supported byposts 5 5, at some distance above said side and end walls, so that theproducts of combustion resulting from the bur'ning of the brick inthekilri will pass over said side and end Walls and laterally beneathsaid roof into the atmosphere. Along the base of each side wall 2 is aseries of ovens .6, communicating with the kiln-chamber through fines 7,opening into said chamber at or near. the floor 1. Approximately midwaybetween and parallel to the side walls 2 2 a duct 8 extends horizontallythrough. the ground be neath the floor 1, and from said duct ports orpassages 9 extend upwardthrough the floor 1 into the kiln-chamber.-InFig. 3 three such kilns are shown diagram, and each duct 8communicates at oneendof its kiln with a duct 10 and at its other endwith a duct -11, the duct lfl leading from-a fanTIHZ,

e number of saidkilns may and'for economy in operation should be morethan three. Between each such kiln and the duct 10 the ducts 8 areprovided Withgates' or dampers 13, and-betweensaid kilns andthe duct 11said ducts 8 are provided with similar gates or dampers14. It Will beobserved .thatthis arrangement of said flues and said fan providesmechanical means for driving gases through the ducts 8 and ports orpassages 9-into any one of said kiln-chambersor drawin gases from saidkiln-chamber downward at rough,

said ports or passages into the ductS, the gate 13 beingleft open-andthegate 14being closed for-the formeroperation and the positions of saidgates being reversed for the latter operation, the fan beingsetandoperated to take gases fromthe duct 11 and discharge them into theductlO. p

The operation is as follows: The furnaces 6 being closed, horizontaltiers of brick care set upon the floor 1, just as brick from the drierare vordinarily set in such akiln preparatory to burning, the brickbeing extended to or-against each side wall 2 but the number of layersis limited, according to the plasticityof said brick. In other words,said rick are set only asrhigh' as they-Would be in a drier-from about,five to ten highif they are of stiff clay, in order that .the bricks inthe lower layers ma not be pressed out of shape by the weight 0 the.superposed the side walls 2 2, so that said brick are isolated in acompartment in the lower portion-of the kiln-chamber. Said coverv may bepaper or sheet metal, or any other suitable sheet-form material capableof withstanding the relatively low heat under which the brick are to bedried. The said group cf bricks being thus isolated, a gaseous dryingmedium is now driven through the duct 8 and from the latter through theports (1' passages 9 into the central lower portion of said group, andthence upward and laterally tcward each lateral wall 2 and upwardthrough the space a between said cover and said lateral walls, andthence through the upper portion of the kiln-chamber into theatmosphere, said cover, as is obvious from an inspection of thedrawings, serving to deflect the rising gaseous medium horizontally.This operation is continued until said group of' bricks has beensufficiently dried for the setting of additional superposed groups. Thensaid cover I) is removed and another group is set upon the first groupand a cover I) placed upon said second group a and a drying gaseousmedium again driven through the duct 8 and from the latter through theports or passages' into the base of the mass of brick and upward throughthe latter until said stream of gaseous medium is deflected horizontallyby said cover toward each lateral wall 2 until the opening between thelateral edges of said cover and said walls is reached, where saidgaseous medium escapes into the upper portion of the kiln-chamber andthence into the atmosphere. This operation is repeated until the kilnhas been char ed as high as desired. It will be observed that inasmuchas said drying gaseousmedium is driven upward through the passages 9 itstendency is to rise, and such movement is only terminated by thedeflecting action of the horizontal cover 6, and such tendency to riseis all the more pronounced if the drying gaseous medium is hot, as isusually its condition. if it be desired to facilitate the upwardmovement of said gaseous medium,-the brick in all of the groupsexcepting the up permost may be set with flue-spacing (1 (continuous orinterrupted) above the ports or passages 9. Obviously such flue-spacingmay, if so desired, be extended also into the uppermost group a; but itsomission has been above suggested because such extension is deemedunnecessary. When the mass of. brick has in this manner been set to theheight desired and thus dried group by group, the entire mass of saidbrick may be further the same orhigher temperature through the joiningkilns.

called waste heat. Such utilization may.

duct 8 and from the. latter through the ports or passages 9 into andthrough the-entire mass of said brick, the cover I) being left upon theuppermost group, if so desired, or such additional drying may beaccomplished by closing the duct 8 and opening the furnaces 6 andallowing. the products of combustion from moderate fires in saidfurnaces to pass through the flues 7 and thence through the entire massof brick. When the entire mass of brick is sufliciently dried forburning, (either by the exposure of each separate group to the action ofthe drying agent or by such separate exposure and the subsequentexposure of the entire mass to the dryin agent,) the entire mass ofbrickis subjecte to the intense heat'of products of combustion comingfrom strong fires maintained in said furnaces, this burning-step beingby itself the same as is now ordinarily practiced in open-top kilns. Tofacilitate or regulate the move-' ment of the products of combustionfrom the furnaces 6 through the flues;7 into the mass of brick, thelower courses of the brick may be set with suitable horizontal spacing,as is now thepra'ctice in operating kilns of this type. After the entirecharge or mass of brick has been burned the air heated during the periodof cooling of said brick may be utilized in dryin the brick inone ormore adfn this art such heated air is be eifected by means of the aparatus illustrated in Fig. 3. If the rightand kiln in said figure hasbeen charged and the burning of said charge completed and one of theother kilns in said fi ure is bein charged then the IOC gate 13 of saidright-ham 'kiln'ls closed and the gate 14 of the same kiln opened, whilethe gate 13 of the next kiln is opened and the gate 14 of the same kilnis closed Then the operation of the fan 12 will exhaust the air from theduct 8 of the first kiln through the duct 11 and drive said air throughthe duct 10 into the duct 8 of the next kiln and throu h said'duct 8into said next kiln. For the 'sa e of economy the operation of chargingand drying should be carried on simulta neously in two kilns, a group ofbrick being set .in one, while a fresh group is being subjected to theaction of a' drying agent in theother of said two kilns. When this isdone, the hot air or waste heat drawn from the'cooling-kiln, as abovedescribed ,may be driven alternately into said two kilns, so that saidwaste heat is uninterruptedly utilized. In theaverage of theseoperations the waste heat is suflicient for drying all the brick, -'andif-such .waste heat be uninterruptedly and'constantly used in the mannerabove indicated the direct application of products of combustion fromthe I furnaces for any portion of the drying operation is unnecessary.dried by driving'a drying gaseous medium of 1 As to its main or genericamass open top kiln shown by Figs. 1 and 2. Inv said Figsal andthe'floor 1, side walls 2, .end

walls 3, furnaces 6, flues 7, underground duct .8, and ports or passages9 are present, as in .Figs. 1 and 2; but in lieu of the roof 4 of Figs.

1 and 2 there is an arch 4*, supported by the lateral walls 2, and insaid arch are crownports 4 provided-with covers 4, and adjacent to andparallel with the inner face of each lateral wall 2 is a bag-wall 15,rising from the floor 1 to any desired height, preferably high enough toadapt said kiln for burning by a downdraft. The-brick are set in groupsin this kiln just as they are in the kiln shown by Figs 1 and 2, thebrick extending laterally tc or against each bag-wall, (said bag-wallbeing, in :efliect, the lateral wall of the kilnoompartment or charnpen)and the drying operation is carried on group by group in the samemanner, thefurnaces being closed and the-crown-ports 4 beingopen for theescape of the drying agent after escaping from the uppermost group ofbrick, and the drying operation may be extendedafter the last grouphasboen set by continuing the driving of. the gaseous medium throughthe.duct 8 and the ports or passages 9-or by driving. the products ofcombustion from a moderate fire in said furnaces upward through. thespace between the lateral walls 2 and the bag-walls 15 into the upper.portion of the kiln-ohamberand thence downward through the mass ofbrick, the movement of said products of. combustion through thecourse-indicated being stimulated or forced by exhausting the airandsaid roducts of combustion-from the duct 8. Wlientlte'ientire mass ofsaid brick is ready for burni'n the burning operation-is carried on bybuilding intense fires-in said furnaces and exhausting the air andproducts of combustion from the duct 8, whereby the products ofcombustion from said furnaces ass through the fines 7, the spacesbetween t e lateral walls 2,,and- I -plastic,material, which methodcpnsists in the bag-walls 15 into the upper portion of thefurnace-chamber and thence downward through the mass of brick, the portsor passages 9, and the duct 8. Fig. 3 is a diagrammatic representationof this form of kiln, as well as of the opemtop form of kiln, and whenthe ducts 10, 11, and Sand the fan 12 and gates-l8 and :14 are arrangedas shown in said ure, in conmaction with the closed form of fi ki 11,the products of combustion enteringtle duct 8 during the burning eriodmay be drawn into the duct 11 and through the fan 12 and thence throughthe duct 10 into another duct 8 and from the latter into thekiln-chamber, under which said duct extends, and thence passed throughgreen'brickset in said kiln for drying in the manner already describedinconnection Withthe open-top kiln. Thus it will be seen that inconnection evenly into the mass of blocks,

The construction shown by Fig. 6 differs i from that shown by Figs. 4and 5on1 in that the furnaces 6 and the bag-wallat t e righ'thand sideare omitted and stacks or chimneys 16 are placed along said side of thekiln and made to communicate with the'kiln-chamber through a port 17,placed at or'ne'ar the base of eachstack. In this kilnlfhe'drying'operation is carried on as described in connection with Figs. 4 and 5,while during the burning operation the productsof combustion may beexhausted through the duct 8 or through the stacks 16, as may bedesired.

In Fig. 7 the duct8 is provided with horizontal branches 8, from whichorts or passa es 9 extend upwardthrougli the floor 1 W on the kiln isthus'constructed, the drying gaseous medium driven into the duct 8issues from the ports or passages 9 andalso-passes .into the branches '8and issues from the ports or passages-9 By this means the drying agentmay be introduced approximately etweenthe lateral wallsol said mass, andallowed to rise through said mass without lateral deflection by a coveror similar means placed upon the then uppermost group of 'green blocks.

1 claim as my inventioni, The herein-described method of treatingplastic material, which 'method consists in forming said material,in'the reen state, into blocks; then setting said bloc s in a pluralityof superposed groups; driving a dryingagent upward between the uprightsides of the mass of blocks after the setting of each group, anddeflecting said drying agent lateral y throughthe last set grou and thensubjecting theentire mass 0 said blocks to a high temperature,substantially as described.

2. The herein-described methodof t'reating orming said material, in thereenstate, into blocks; then setting said blorfirs ina plurality ofsuperposed gIOlPS within a compartment, said-groups exten ingtooragainst thelateral walls of the compartment and having an upright fluespacing bewe'ensaid lateral walls, each successive grou being sub'ectedto the action of an artificia lymoved rying agent. before another. grouis set thereon,

said drying agentbeingma to rise throu said ue-spacing and move thencelateral y through the thenlast ofsaid groups and then upward out of saidgroup; and then subectr ingxthe entire mass of said blocks'to a, ightemperature, substantially as described.

3. The herein-described method of treating lastic material, which methodconsistsin orming said material, in the green state, into L blocks; thensetting said blocks in a plurality of superposed groups within acompartment, said groups extending to the lateral walls of thecompartment and all excepting the uppermost group having an uprighttlue-spac ing between said lateral walls; each successive grou beingsubjected to the action of an artificial *-moved dpying agent beforeanother grdup is set thereon, said drying agent being made to risethrough said flue-spacing and move thence laterally through the thenlast of said groups, and then upward out of said group; and thensubjecting the entire mass of said blocks to a high temperature,substantially as described.

a. The herein-described method of treating plastic material, whichmethod consists in orming said material, inthe green state, into blocks;then setting said blocks in a plurality of superposed groups within acompartment, said groups extending to the lateral walls of thecompartment and having an upright fluespacing between said lateralwalls, each successive group being subjected to the action of an artiiicially-moved drying agent before another group is set thereon, saiddrying agent being made to rise through said flue-spacing and movethence laterally through the then last of said groups and then upwardout of said group and then passing a highly-heated gaseous medium intothe base of said mass and thence through said mass, substantially asdescribed.

5. The herein-described method of treating plastic material, whichmethod consists in forming said material, in the green state, intoblocks; then setting said blocks in a plurality of superposed groupswithin a compartment,

said groups extending to the lateral walls of the comp artinent andhaving an upright'fluespacing between said lateral walls, eachsuccessivegroup being subjected to the actionof anartificially-moved drying agentbefore another group is set thereon, said drying agent being made torise through said flue-spacing and move thence laterally through thethen last of said grou s and then upward out of said group; and t enpassing a highly-heated gaseous medium into the base of said mass fromopposite sides and thence through said mass, substantially as described.

6. 'The herein-described method of treating plastic materialfwhichmethod consists in forming said material, in the green state, intoblocks then'setting said blocks in a-plurality of superposed groupswithina compartment, said groups extending to the lateral walls of saidcompartment, a cover being placed 11 on each successive group, saidcover eXten ing almost to the lateral edges of said group and said groubeing then subjected to the action of an arti icially-moved drying agentmade to rise centrally through said group beneath said cover, and saidcover being then re: moved before another group is set thereon";

orming said material, in the of superposed groups driving a drying agentupward between the upright sides of the mass 0 blocks after the settingof each group, and deflecting said drying agent laterally through thelast set group; then subjecting the entire mass of said blocks to a hightemperature, and then passing air downward through said mass and thencethrough another group of green blocks, substantially as described.

8. The herein-described method of treating plastic material, whichmethod consists in forming said material,in the green state, intoblocks; then'setting said blocks in a plurality of superposed groupswithin a compartment, said groups extending to oragainst the lateralwalls of the compartment and having an upright flue-spacing between saidlateral walls, each successive group being subjected to the action of anartificially moved drying agent before another group is set thereon,said drying agent being made to rise through said fluespacing and movethence laterally through the then last of said groups and then upwardout of said roup; then subjecting the entire mass of said blocks to ahigh temperature, and then passing air downward through said mass andthence througlLanother group of green blocks, substantially asdescribed. Y

' 9. The herein-described method of treating plastic material, whichmethod consists in reen state,1nto

blocks then setting said blochs in a plurality of superposed groupswithin a compartment, said groups extending to the lateral walls of thecompartment and all excepting the uppermost group having an uprightflue-spacing between said lateral walls; each successive group beingsubjected to the action of an artificially-moved drying agent beforeanother group is set thereon, said drying agent being made to risethrough said flue-spacing and move thence laterally through the thenlast of said groups, and then upward out of said roup then subjectingthe entire mass of said locks. to a high temperature; and then passingair downward through said mass and thence through another group of greenblocks, substantially as described.

, '10. Theherein-described method of treating plastic material, whichmethod consists in forming said material, in the green state, intoblocks; then setting said blocks in a plurality of superposed groups;and, after the settin of each group driving a drying a ent into the baseofsaid inass of blocks between the upright sides of said mass and thencethrough said mass; and then subjecting the entire mass of said blocks toa high tempera ture, substantially as described.

11. The herein-described method of treating plastic material, whichmethod consists in forming said material, inthe green state, intoblocks; then setting said blocks in a plurality of superposed groups;and, after setting each group, driving av drying agent into the base ofsaid mass of blocks between the upright sides of said mass and thencethrough said mass; then subjecting the entire mass of said blocks to ahigh temperature; then passing a stream of air through said mass andthence through another group of green blocks. substantially asdescribed.

12. The herein-described method of treating plastic material, whichmethod consists in forming said material, in the green state, intoblocks: then setting said blocks in a plu rality of superposed groups;and, after the setting of each group, driving a drying agent upwardthrough said mass; then subjecting the entire mass of said blocks to ahigh temperature; and then passing air downward through said mass,substantially as described.

13. The liere'in-described method of treating plastic material, whichmethod consists in forming said materal, in the green state, intoblocks: then setting said blocks in a plurality oi superposed groups;and, after the setting of each group, driving a drying agent upwardthrough said mass; then subjecting the entiremass of said blocks to ahigh temperature; then passing air downward through said mass andthence-to and through another group of green blocks, substantially asdescribe 14. The herein-described method of treating plastic material,which method consists 40 in forming said material, in the green state,-into blocks; then setting said blocks in a pip 'rality of superposedgroups; driving air at moderate temperature upward between the uprightsides of the mass of blocks after the setting of each group, anddeflecting said air through the last-set group; and then subjecting theentire mass of said blocks to a high temperature, substantially asdescribed.

15. The herein-described method of treating plastic material,whichmethod consists in forming said material, in the green state, intoblocks; then setting said blocks in a plurality of superposed groups;driving air at moderate temperature upward between the 5 5 upright sidesof the mass of blocks after the setting of each group, and deflectingsaid air through the last-set group; then subjecting the entire mass ofsaid blocks to the action of a drying agent; and then subjecting theentire mass of said blocks to a high tempera ture, substantially asdescribed.

In testimony whereof I have signed my name, in presence of twowitnesses, this 10th day of November in the year 1905.

ALEXANDER ANDERSON SCOTT.

Witnesses CYRUS Kenn, RoBT. IJ. FoUs'r.

